The invention relates to a connector arrangement for use in a fuel system. In particular, the invention relates to a connector arrangement whereby a plurality of high pressure fuel pipes can be connected, and sealed, to a housing. The invention also relates to a connector arrangement for permitting a plurality of high pressure fuel pipes to be connected to a plurality of fuel injectors in an internal combustion engine.
Conventional high pressure fuel pipe connector arrangements are relatively bulky, thus where a plurality of pipes are to be connected to a common housing, the housing must be relatively large. It is thought that the complexity of a common rail fuel system may be reduced by connecting the high pressure fuel pipes for the various injectors directly to an accumulator housing or other housing associated with the fuel pump. However, as conventional connector arrangements are relatively bulky, the connection of several such pipes is difficult. It is one object of the invention to provide a connector arrangement suitable for use in such applications.
It is also a requirement in such systems to connect each of the injectors to a common high pressure fuel supply. It is a further object of the invention to provide a connector arrangement which achieves this function.
According to a first aspect of the invention, there is provided a connector arrangement for use in a fuel system, the connector arrangement comprising a bridge member shaped for cooperation with at least first and second members to be connected to a housing, and clamp means for clamping the bridge member to the housing, the bridge member transmitting a clamping load from the clamp means to the first and second members.
In particular, but not exclusively, the connector arrangement is suitable for use in an engine. The first and second members may both comprise fuel pipes. Alternatively one of the first and second members may comprise a blanking member.
The housing conveniently comprises an accumulator housing of a fuel pump, the housing being provided with passages whereby, in use, an accumulator chamber located within the accumulator housing communicates with the or at least one of the fuel pipes. Alternatively, the housing may comprise a manifold suitable for mounting at an outlet of a fuel pump.
The clamp means may comprise a bolt which extends through the bridge member and which is in threaded engagement with the housing. Alternatively, the clamp means may include a screw-threaded clamp arrangement and a load transmitting member arranged to transmit the clamping load to the bridge member. Conveniently a plurality of bridge members are provided, the load transmitting member transmitting the clamping load to all of the bridge members.
According to a second aspect of the invention there is provided a connector arrangement comprising a manifold to which a plurality of fuel pipes are permanently mounted.
The manifold is conveniently adapted to be mounted at an outlet of a fuel pump. The fuel pipes may, for example, be brazed or welded to the manifold.
By providing techniques whereby a plurality of fuel pipes can be secured to a manifold or housing, it will be appreciated that the provision of a separate common rail can be avoided, and hence that a xe2x80x9ccommon railxe2x80x9d type fuel system of reduced complexity can be provided.
According to a third aspect of the present invention, there is provided a connector arrangement for use in a fuel system, the connector arrangement comprising a plurality of high pressure fuel pipes which are supplied with fuel from a common inlet passage, the common inlet being arranged, in use, to receive fuel from a high pressure fuel supply, each of the pipes comprising one or more outlet region which is connectable with an inlet region of a respective injector forming part of the fuel system to permit high pressure fuel to be supplied to said injector.
The connector is particularly suitable for use in supplying fuel to an internal combustion engine.
Conveniently, each of the high pressure fuel pipes defines at least one flow passage for fuel between the common inlet passage and the inlet region of an associated injector.
Preferably, each of the flow passages for fuel has substantially the same length. As fuel is supplied to each of the injectors along a flow passage having substantially the same length, fuelling consistency between the injectors is improved.
Conveniently, one or more of the high pressure fuel pipes may be provided with an attachment member for attaching a component to the respective high pressure fuel pipe. For example, the attachment member may be used to mount an electrical connector, electrical wiring or a low pressure fuel pipe on the high pressure fuel pipe.
As the connector arrangement according to the third aspect of the present invention can be relatively compact, the connector arrangement may be mounted, in use, under the cam cover of the engine.
Preferably, the connector arrangement may comprise two high pressure fuel pipes, each of the pipes defining two flow passages for high pressure fuel, each of the flow passages permitting fuel to be delivered from the high pressure fuel supply to the inlet region of an associated injector.
Conveniently, the common inlet passage is arranged to communicate with each of the high pressure fuel pipes a part of the way along the length of each of the pipes.
Conveniently, the connector arrangement may include an inlet member which defines the common inlet passage for fuel.
The inlet member may be provided with two through bores, each of the bores having a high pressure fuel pipe extending therethrough. As the high pressure pipes extend through the inlet member, the forces on the high pressure pipes are balanced and the pipes are not subjected to undesirable axial forces.
Each of the high pressure fuel pipes may be provided with a cross drilling to permit communication between the high pressure fuel pipe and the common inlet passage.
At least one of the high pressure fuel pipes may be provided with a closure member to seal an open end of the respective fuel pipe. In particular, this embodiment of the invention may be used in an engine having an odd number of injectors.
The connector arrangement may further comprise a seal assembly for providing a substantially fluid tight seal between the connector arrangement and, for example, the cam cover and/or the engine block of the engine in which the connector arrangement is used.
According to a fourth aspect of the invention, there is provided a seal assembly for use with a connector arrangement as herein described, the seal assembly comprising a resilient seal member and first and second plate members, the first and second plate members being arranged to apply a force to opposing faces of the seal member such that, upon assembly of the seal assembly, the application of a force to at least one of the plate members serves to deform the seal member into sealing engagement with a surface associated with the fuel system.
Conveniently, the seal member may be arranged to sealingly engage a surface of a cam cover or engine block of the associated engine.
The seal member may be provided with a substantially flat surface for engaging a substantially flat surface of the engine block or the cam cover to provide a substantially fluid tight seal. Alternatively, the seal member may be arranged to be received within an aperture in the cam cover or the engine block of the engine.
The connector arrangement may include a further pipe and a further inlet member, the further pipe being arranged to communicate with the common inlet passage and a high pressure fuel supply. Conveniently, each end of the further pipe may be arranged to communicate with the common inlet passage of a connector arrangement in accordance with the present invention. This embodiment of the invention is particularly suitable for use in xe2x80x9cveexe2x80x9d type engines.
According to a fifth aspect of the present invention, there is provided a method of manufacturing a connector arrangement as herein described comprising the steps of;
providing an inlet member with at least one through bore;
inserting a pipe for carrying high pressure fuel through the bore in the inlet member; and
forming an inlet passage through the inlet member such that the inlet passage communicates with a flow passage defined by the pipe to permit fuel in the inlet passage to be supplied to the flow passage, in use.